The present invention concerns an RF signal switch for providing a high degree of isolation between sources in both the energized and de-energized condition.
It is common for several high frequency (RF) signal sources to be switched at the tuner inputs of an RF receiver such as a television receiver or the like. In such an arrangement it must be guaranteed, that there is sufficient de-coupling between the signal sources. In the United States, the FCC requires attenuation values of more than 80 db for frequencies up to 220 MHz. These values must also be observed in the shut-off condition. Often the RF signal sources are switched-over by the assistance of special relays. In order to make these relays usable for radio frequency, they must be realized using a stripline technique. However, the stripline relay technique is very expensive, and the space required for such a relay and the measures concerning construction and circuitry are very great. Additionally, the life expectancy is limited due to the moving parts.
The present invention is directed to a circuit arrangement overcoming such deficiencies.